fast_coprocessor exception handler expects that the coprocessor owner task never gets the "coprocessor disabled" exception for a coprocessor that is marked as enabled in the thread_info::cpenable. If that happens it will reload potentially outdated context from the thread_info structure into the coprocessor registers. Only call coprocessor_clear_cpenable from the coprocessor_release_all if the latter is called for the current task.
Cc: stable@vger.kernel.org Signed-off-by: Max Filippov jcmvbkbc@gmail.com --- arch/xtensa/kernel/process.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c index 3fa0c440f664..6c7c80106f60 100644 --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -87,7 +87,8 @@ void coprocessor_release_all(struct thread_info *ti) }
ti->cpenable = cpenable; - coprocessor_clear_cpenable(); + if (ti == current_thread_info()) + coprocessor_clear_cpenable();
preempt_enable(); }